In modern lives, desktop computers have become essential home appliances for small and medium-sized families. Generally, the host of the home computer is equipped with a cooling fan. The cooling fan is used for dissipating the heat from the casing of the host. Since the overheating problem is avoided, the processor, the motherboard or the hard drive in the host is not damaged.
For meeting the requirements or preferences of different users, a computer host with a transparent casing has been introduced into the market. The inner structure or condition within the computer host can be directly observed through the transparent casing. Moreover, the computer host may be further equipped with a luminous fan. When the computer host is turned on, the luminous fan emits a light beam and the luminous fan is operated to remove heat. Consequently, the computer host is operated stably and the appearance of the computer host becomes more modern.
Nowadays, the trends of designing the computer host or the electronic device are toward slimness and miniaturization. For achieving this purpose, the volume of the luminous fan needs to be reduced. Accordingly, the solid state light sources (e.g., light emitting diode) with small size and high luminous efficiency have been widely used in the illumination modules of various luminous fans.
However, the use of the solid state light source still has some drawbacks. For example, since the light beam from the solid state light source travels along a linear trajectory, the diffraction angle is small. As the volume of the luminous fan is reduced, the propagation path of the light beam is shortened and the projection area of the light beam is centralized. Consequently, the overall luminous intensity of the luminous fan is reduced. Since the light beam is centralized, the brightness of the projected location of the light beam is not uniform, and hot spots are generated at the projected location. Due to the generation of the hot spots, the luminous fan cannot provide the uniform luminous efficacy.
For solving the drawbacks of the conventional technologies, the present invention provides a luminous fan for increasing the light utilization efficiency, enhancing the overall luminous intensity and avoiding the generation of the hot spots.